This invention relates to entering and displaying two-dimensional information on a computer.
Flat panel displays for portable computers, for example, can display text and graphics as an array of binary, gray scale, or color pixels.
So-called touch pads can determine the location and trajectory of a finger, pen, or stylus on the surface of the pad to permit a user to point to a location or to draw or write information for entry to a computer. Some touch pads also provide a simultaneous display of the information being entered.
Scanners can scan a document to provide a digitized version of the document to a computer.
A variety of display and detection technologies have been used to provide the features of displays, touch pads, and scanners, including liquid crystal displays (LCDs), electroluminescent and gas plasma displays, magnetorestrictive and resistance based devices, and photoconductor arrays. Some display devices employ a hysteresis effect.